Diversity of Mammals

5th Grade

There are 3 main groups of mammals. These groups differ in how their young develop.

3 main groups of mammals:

• 1) Monotremes

• 2) Marsupials

• 3) Placental Mammals

Monotremes are still considered mammals because they drink milk from their mother’s

skin• An Anteater lay eggs directly into a pouch in

the mother’s belly • A Duck-billed platypus lays her eggs in an

underground nest

Monotremes

Monotremes

• Egg-laying mammals

• ONLY 3 SPECIES:-2 species of anteaters-Duck-billed platypus

Why are these still considered mammals?

Marsupials

• Mammals whose young are born at an early stage of development, and they usually continue to develop in a pouch on the mother’s body

• short gestation period: the length of time between fertilization and birth

When born, marsupials are blind, hairless, and pink!

Examples of Marsupials

• Kangaroos• Wallabies• Koalas• Wombats• Tasmanian Devils• Possums• Gliders

Marsupials - Kangaroo

Marsupials—Wallaby

Marsupials-Koala

Marsupials--Wombat

Marsupials—Tasmanian Devil

Marsupials--Possums

Marsupials--Gliders

Placental Mammals

• Develops inside its mother’s body until it can function independently

• Name comes from placenta: an organ in pregnant female mammals that passes materials between the mother and the developing embryo

• Food and oxygen pass from the mother to her young

• An umbilical cord connects the young to the mother’s placenta.

Most mammals are placental mammals

• The gestation period for animals usually depends on their size

• Elephants have a 21 month gestation period

• Mice have a 20 day gestation period

Placental Mammals are grouped based on how they eat and move

Placental Mammals – Carnivores: have large canine teeth and clawed toes to catch prey

• River Otters

• Dogs

• Raccoons

• Seals

Placental Mammals - Rabbits and Hares – Leaping mammals with long hind legs & long, curved incisors for gnawing

Placental Mammals -- Marine Mammals (marine = ocean)

• Whales

• Manatees

• Dolphins

Placental Mammals –Rodents –are gnawing mammals such as mice rats, beavers, capybaras

• Rats

• Mice

• Beavers

• Capybaras

Beaver

Capybara

Placental Mammals – Trunk-nosed mammals

• Elephants

• Woolly Mammoth (extinct)

Placental Mammals – Flying Mammals

• Bats –their wings are made of a thin skin that stretches from their wrists to the tips of their long finger bones

Flying Fox Bat

Placental Mammals – Insectivores

• Moles

• Shrews

Placental Mammals - Primates

• Have large brains and eyes that face forward

• Include humans, monkeys, chimpanzees, orangutans, lemurs, etc.

Placental Mammals –Primates-Gorilla

Placental Mammals –Primates --Chimpanzees

Placental Mammals –Primates --Gibbons

Placental Mammal –Primates -Lemur

Placental Mammals--Primates--Bush babies

Placental Mammals –Primates--Marmocet

Placental Mammals –Primates -Tamarin

Placental Mammals –Primates-Toothless Mammals

• Have either very small or no teeth – Armadillos– Sloths

Placental Mammals –Primates - Hoofed Mammals

• Cows• Deer• Pigs• Horses• Zebras

Caring for Young

• Monotremes, Marsupials, and Placental Mammals all care for their young

• Baby mammals are helpless for a long time after being born –many are born blind or without insulating fur

• Young mammals stay with their mothers or both parents for an extended period of time

Rhinoceros with baby

Chimpanzee mother and baby

Mother with lion cubs

Colobus Monkey with baby

Labrador with babies

Polar bear with baby

Panda Bear mother with baby